题解 | #二叉搜索树的最近公共祖先#

/**
 * struct TreeNode {
 *  int val;
 *  struct TreeNode *left;
 *  struct TreeNode *right;
 *  TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
 * };
 */
class Solution {
  public:

    int lowestCommonAncestor(TreeNode* root, int p, int q) {
        if ((q > root->val && p > root->val) || (q < root->val && p < root->val)) {
            return lowestCommonAncestor(q > root->val ? root->right : root->left, p, q);
        }
        return root->val;
    }
};